Slide fasteners

ABSTRACT

There is provided a slide fastener comprising a pair of opposed carrier tapes and rows of interlocking fastener elements mounted thereon. Each tape consists of a warp-knitted structure having wales of warp stitches connected coursewise by laid-in weft threads and alternated with grooves wider than said wales. These grooves are substantially filled with reinforcing warp threads to attain dimensional stability of the tape particularly at the longitudinal edge thereof along which the fastener elements are secured.

111 3,849,842 1451 Nov. 26, 11974 SLIDE FASTENERS [75] Inventor: Tadahiro Yoshida, Fujisawa, Japan [73] Assigneez Yoshida Kogyo Kabushiki Kaisha, Tokyo, Japan 22] Filed: Aug. 16,1972

21 Appl. No.: 280,998

I [30] Foreign Application Priority Data Aug. 18, 1971 Japan 46-62746 Aug. 18, 1971 Japan 46-62747 Aug. 18, 1971 Japan 46-62748 [52] US. Cl. 24/2051 C, 24/205.l6 C, 66/195 [51] Int. Cl A44!) 19/12 [58] Field of Search 24/2051 C; 66/195 [56] References Cited UNITED STATES PATENTS 3 ,1 2 ,3 7 9/1964 Ruhrmann 24/205,16C

3,430,304 3/1969 Swainson 24/2051 C 3,520,155 7/1970 Koppenburg 66/190 3,540,084 11/1970 Frohlich 1 24/2051 C 3,665,733 5/1972 Jackson .1 66/86 7/1972 Jackson 66/86 3,708,836 l/l973 Frohlich 3,714,683 2/1973 Frohlich 24/205.l6 C 3,728,876 4/1973 Richard 66/195 FOREIGN PATENTS OR APPLICATIONS 1,228,038 4/1971 Great Britain 24/2051 C OTHER PUBLICATIONS Knitted Outerwear Times, -Wheatley, Co-We-Nit, pages 47-54.

Primary ExaminerBernard A. Gelak Attorney, Agent, or Firm-Bucknam & Archer [5 7 ABSTRACT There is provided a slide fastener comprising a pair of opposed carrier tapes and rows of interlocking fastener elements mounted thereon. Each tape consists of a warp-knitted structure having wales of warp stitches connected coursewise by laid-in weft threads and alternated with grooves wider than said wales. These grooves are substantially filled with reinforcing warp threads to attain dimensional stability of the tape particularly at the longitudinal edge thereof along which the fastener elements are secured.

4 Claims, 6 Drawing Figures SLIDE FASTENERS This invention relates toslide fasteners and has particular reference to fasteners comprising a pair of opposed carrier tapes generally of a warp knitted structure and rows of interlocking fastener elements attached along one or inner longitudinal edges of the reers made of woven fabric stringer tapes. However, they have suffered from reduced mechanical strength and less dimensional stability compared to woven fasteners. Attempts have been made to improve these factors for instance by employing different kinds of knitting yarns, or by laying warp threads in between wales of the knitted system. None of these attempts were successful. The use of two or three different kinds of yarns did not solve the problems of stretch both longitudinal and transverse of the carrier tape and positional instability of fastener elements relative to their supporting tape. The approach of laying warp threads in between wales was frustrated by the fact that the grooves defined between adjacent wales are limited in width as inherent in warp-knitted structures and wide enough to receive only one or two warp threads and that it is difficult to According to the invention, there is provided a slide fastener comprising a pair of opposed carrier tapes of a warp-knitted structure, rows of interlocking fastener elements mounted thereon, each of said tapes having wales of warp stitches connected coursewise bylaid-in weft threads and alternated with grooves greater in width than said wales, a plurality of reinforcing warp threads adapted to fill said grooves substantially waleto-wale and a line of sewing stitches securing said rows of fastener elements to said carrier tapes and running through the filled grooves adjacent the respective one longitudinal edges of said carrier tapes.

direct and positionthe sewing needle stably in such 1 narrow grooves and to prevent the sewing stitches from movinglaterally between the wales with the result that the fastener elements become displaced from their properly aligned position on the fastener.

Whereas, it is an object of the present invention to eliminate the above-mentioned difficulties of the conventional knitted fasteners, and more specifically to provide an improved knitted slide fastener having. a pair of warp-knitted carrier tapes which has a mechanical strength and a dimensional stability comparable to those of woven fabrics particularly at the longitudinal edge portion of the'ca'rrier tape along which fastener elements are secured, thereby maintaining the fastener elements in the properly aligned position on their respective carrier tapes during the opening and closing operation of the fastener.

It is another object of the invention to provide an improved knitted slide fastener having a pair of warpknitted tapes which permits the sewing'needle to run correctly. through and along the grooves between wales so as to attach the fastener elements securely in correct alignment onto their respective supporting tapes and which has sewn stitches securely anchored in the grooves against lateral displacement, thereby ensuring Referring now to the drawings and FIGS. 1 and 2 in particular, there is shown a first embodiment which 1 comprises a pair of opposed carrier tapes T, T each tener elements E are secured into position. These grooves 11 are adapted to receive therein a plurality of warp threads 12 in a manner to cover the bottom wall of the grooves and fill the same substantially wale-towale as shown. This arrangement provides reinforcement particularly at an-extreme inner edge region of the tape T defined between the first and second wales W W or corresponding to the innermost groove 11,

which region would otherwise be coarse and mechanically weak in the absence of the filling warp threads 12. The fastener elements E shown as being interlocked are secured to the inner edge of the tape T by a, line of sewing stitches S spanning between the leg portion Ea of the fastener element E and the innermost groove 11, running through a stiffening core 13 and the innermost groove 11 and extending longitudinally of the tape T.

The groove 11 in particular is wider than adjacent wales W W This advantageously ensures that the sewing needle (not shown) is accepted and guided desirably within the longitudinal groove 1 1 without causing the needle to swerve onto the wale W or W thereby sewing the row or fastener elements E into cor- FIG. 3 is a magnified plan view of another embodiment of the invention;

FIG. 4'is a sectional view of the same;

FIG. 5 is a magnified plan view of a further embodiment of the invention; and

FIG. 6 is a sectional view of the same.

rect, aligned position on the carrier tape T. Also advantageously, the reinforcing warp threads 12 which are intimately compacted together within the groove 11 serve to hold the sewing stitches S firmly in place under the tension of the warp threads 12 which are directed laterallyt owards each other. This will maintain the proper position and posture of the fastener elements E under severe stresses applied by a reciprocating slider 30 (shown in FIG. 4) or against lateral forces tending to pull apart the closed stringers.

While the first embodiment. described above is constructed to provide a dimensional stability particularly warp-wise of the tape T as this is critically important, the second embodiment shown in FIGS. 3 and 4 considers the dimensional stability both warp-wise and weft-wise of the tape. The fastener shown in FIGS. 3 and 4 is provided with a thickened, reinforced edge 15 extending longitudinally of the tape T and formed by wales W W and innermost groove 11 defined thereby, which groove is substantially wider than the remaining grooves 11 in the tape T. The reinforced edge or element-mounting edge 15 has more reinforcing warp threads 12 and more laid-in weft threads a than there are in the remaining portion or web 16 of the tape T, so that at least the said edge of the tape T retains increased dimensional stability in both longitudinal and transverse directions and hence, the elements E mounted thereon are maintained stably in position against displacement relative to the tape under severe stresses applied by the slider 30, or against lateral forces tending to pull apart the closed stringers.

The third embodiment or modification of the fastener according to the invention shown in FIGS. 5 and 6 is intended to provide a densified reinforced longitudinal edge comprising a plurality of reinforcing warp threads 12a thicker than those warp threads 12 laid-in at the remaining web portion 16 of the tape T and intercrossed with a plurality of laid-in weft threads 10a. With this construction, the reinforced edge portion 20 of the tape T has the innermost groove 11 swollen to a level nearly flush with the first and second wales W W and thus simulates a woven fabric structure and thus has a mechanical strength and dimensional stability comparable thereto. Therefore, the fastener elements'E when mounted on the fastener in a manner already described are securely held in position on the densified, reinforced edge 20 against displacement by lateral forces or under severe stresses applied by the slider 30. To further stabilize the mounting position of the elements E, the innermost groove 11 in the reinforced edge 20 is wider than the remaining grooves 11 in the web portion 16 of the tape T in a manner similar to the second embodiment.

Having thus described the invention, it is to be understood that various other changes and modifications may be made in the specific form and construction illustrated, without departing from the scope of the appended claims.

What is claimed is:

1. A slide fastener comprising a pair of opposed carrier tapes of a warp-knitted structure, rows of interlocking fastener elements mounted thereon, each of said tapes having wales of warp stitches connected coursewise by laid-in weft threads and alternated with grooves greater in width than said wales, a plurality of reinforcing additional warp threads filling the bottom of said grooves substantially wale-to-wale solely along the longitudinal edge portion of said tape and a line of sewing stitches securing said row of fastener elements to said carrier tape and running through said additional warp threads in said groove adjacent the longitudinal edge of said carrier tape.

2. A slide fastener as defined in claim 1 wherein said knitted carrier tape is provided with an innermost groove at said longitudinal edge which is greater in width than the remaining grooves in the web portion of the tape.

3. A slide fastener as defined in claim 1 wherein said longitudinal edge of the tape is densificd by thicker reinforcing warp threads intercrossed with a plurality of laid-in weft threads.

4. A slide fastener as defined in claim 1 wherein said wales are formed by open-pillar stitches.

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1. A slide fastener comprising a pair of opposed carrier tapes of a warp-knitted structure, rows of interlocking fastener elements mounted thereon, each of said tapes having wales of warp stitches connected coursewise by laid-in weft threads and alternated with grooves greater in width than said wales, a plurality of reinforcing additional warp threads filling the bottom of said grooves substantially wale-to-wale solely along the longitudinal edge portion of said tape and a line of sewing stitches securing said row of fastener elements to said carrier tape and running through said additional warp threads in said groove adjacent the longitudinal edge of said carrier tape.
 2. A slide fastener as defined in claim 1 wherein said knitted carrier tape is provided with an innermost groove at said longitudinal edge which is greater in width than the remaining grooves in the web portion of the tape.
 3. A slide fastener as defined in claim 1 wherein said longitudinal edge of the tape is densified by thicker reinforcing warp threads intercrossed with a plurality of laid-in weft threads.
 4. A slide fastener as defined in claim 1 wherein said wales are formed by open-pillar stitches. 